A lift hill, or chain hill, is an upward-sloping section of track on a roller coaster on which the roller coaster train is mechanically lifted to an elevated point or peak in the track. Upon reaching the peak, the train is then propelled from the peak by gravity and is usually allowed to coast throughout the rest of the roller coaster ride's circuit on its own momentum, including most or all of the remaining uphill sections. The initial upward-sloping section of a roller coaster track is usually a lift hill, as the train typically begins a ride with little speed, though some coasters have raised stations that permit an initial drop without a lift hill. Although uncommon, some tracks also contain multiple lift hills.

Lift hills usually propel the train to the top of the ride via one of two methods: a chain lift involving a long, continuous chain which trains hook on to and are carried to the top; or a drive tire system in which multiple motorized tires (known as friction wheels) push the train upwards. A typical chain lift consists of a heavy piece of metal called a chain dog, which is mounted onto the underside of one of the cars which make up the train. This is in place to line up with the chain on the lift hill.

The chain travels through a steel trough, and is normally powered by one or more motors which are positioned under the lift hill. Chain dogs underneath each train are engaged by the chain and the train is pulled up the lift. Anti-rollback dogs engage a rack (ratcheted track) alongside the chain to prevent the train from descending the lift hill. At the crest of the lift, the chain wraps around a gear wheel where it begins its return to the bottom of the lift; the train is continually pulled along until gravity takes over and it accelerates downhill. The spring-loaded chain and anti-rollback dogs will disengage themselves as this occurs.

The cable lift utilizes a cable loop in place of the traditional chain, which is attached to a short section of chain that engages the train's chain hook. Because a cable is much lighter than a chain, cable lifts are much faster than chain lifts and can be used on much steeper hills - even vertical. A cable also requires far less maintenance than a chain. Another advantage to park guests is that a cable lift is very quiet, partly because the main drive winch is located directly beneath the top of the lift, a location which will normally be relatively far from guest-accessible areas.

Despite having several advantages over a chain lift, It has a significant disadvantage, which is that it must return to the bottom of the lift hill after lifting each train (in contrast to a continuously moving chain lift which does not need any kind of resetting). This limits the usefulness of the cable lift in applications where the cable must travel a long distance and the interval between train departures is short.

There are two types of tilt coaster: A standard coaster with a vertical drop at the start (trains enter the vertical drop via an unusual tilt section; after leaving the chain lift, instead of going down a first drop, the rider is held on a horizontal section of track, which then tilts forwards, to become a vertical section, which leads into the drop, then into the rest of the coaster layout); and a thrill lift designed similar to the elevator lift but instead of it bringing the riders up into the horizontal position, it brings them to a vertical and then lets gravity do the rest. This design has not been made yet, the only place where this occurs is in RollerCoaster Tycoon 3, although there is one operating Tilt Coaster in the world, Gravity Max! at Discovery World in Taiwan.

The elevator lift is a new technology used to make the ascension of the roller coaster faster and more comfortable due to the fact all riders are doing is moving vertically up. It is used mostly in indoor rollercoasters like Scooby-Doo Spooky Coaster. As of 2013 only 22 coasters have an elevator lift.[2]

The Ferris wheel lift is a brand new technology that utilizes the favorite Ferris wheel ride and incorporates it into a roller coaster. Created by Premier Rides, it exists on 'Round About' (formerly Maximum RPM) at Freestyle Music Park in Myrtle Beach, South Carolina.[citation needed] It uses a Ferris Wheel like motion to lift the cars to the top, as on a Ferris Wheel. The cars are then released onto the track.

The familiar "click-clack" sound that occurs as roller coaster train ascends the lift hill is not caused by the chain itself. The cause for this noise is actually a safety device used on lift hills -- the anti-rollback device. The anti-rollback device is a standard safety feature, typically consisting of a continuous, saw-toothed, section of metal, forming a linear ratchet.

Roller coaster trains are fitted with anti-rollback "dogs" which are essentially heavy-duty pieces of metal which fall and rest in each groove of the anti-rollback device on the track as the trains ascend the lift-hill. This makes the "clicking" sound and allows the train to go upwards only, effectively preventing the train from rolling back down the hill should it ever encounter a power failure or broken chain.

This feature was derived from the similar feature originally used on the Mauch Chunk Switchback Railway in Pennsylvania, starting in 1846. The two uphill planes that cars were drawn up under the power of a stationary steam engine had two slightly different early forms of this anti-rollback device. The entire concept of the modern roller coaster was also initially inspired by this railroad.